将xml转换为view的方法

android推荐实用xml布局文件来控制UI界面
方法1：setContentView(R.layout.id)
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}

image.png

方法2：inflate方法
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View content = LayoutInflater.from(this).inflate(R.layout.activity_main, null);
setContentView(content);
}

image.png

              ViewGroup contentView = (ViewGroup) MainActivity.this.getWindow().findViewById(Window.ID_ANDROID_CONTENT);
                View contenttop = LayoutInflater.from(MainActivity.this).inflate(R.layout.activity_top, null);
                contentView.addView(contenttop);

这个是覆盖了当前整个界面

  ViewGroup contentView = (ViewGroup) MainActivity.this.getWindow().findViewById(R.id.innerLayout1);
                View contenttop = LayoutInflater.from(MainActivity.this).inflate(R.layout.activity_top, null);

                contentView.addView(contenttop);